Shirt collar



FIG. 1 is a front-right-top perspective view of a shirt collar showing my new design;

FIG. 2 is a back-left-top perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a back elevation view thereof;

FIG. 5 is a right elevational view thereof; and,

FIG. 6 is a left elevational view thereof.

The broken line showing of the shirt in all views is for illustrative purposes only and forms no part of the claimed design. 

CLAIM The ornamental design for a shirt collar, as shown and described. 